I would like to recommend if its possible to make it so that our log in names are not being used for posts in the forums.

some players have the same name for there characters and there log in some do not. for security purposes it would only make sense to allow us to change the name to a display name and not account name that once set could not be changed.

Otherwise is it possible to submit a request to a forum admin to change my display name and not my log in details.

At this time it is not possible. This is one of the changes we are making with the new account system being created.